Women do all the work, but men call the shots—especially when it comes to the really big money.

That's one picture of the foundation world that emerges from the Council of Foundation's new study, 2014 Grantmakers Salary and Benefits Report, which offers the most in-depth look available at foundation staff and leadership.

Here's the finding that jumped out at me:

In 2014, women represented three-quarters of reported grantmaker staff, but just over half of CEOs. Among grantmakers with $1 billion or more in assets, women accounted for just over a quarter of CEOs (28 percent).

What we have here is a good news/bad news story. The good news is that half of all foundations have women CEOs, except for the really large foundations (and there's under 100 such places.) I don't have the comparative stats handy, but I can't imagine that half of CEOs are women in many other sectors. So that's something.

The bad news, obviously, is that this figure is anything but impressive when you consider the composition of foundation staff. As well, the difficulty for women of ascending to the very top of the foundation world, and running the biggest grantmakers, says something important. It's not that there's a glass ceiling, since over a quarter of those foundations are run by women, but rather that boards and living donors do seem more inclined to trust men with the truly big pots of money. Either that or not enough strong female candidates apply for those positions.

This gender gap isn't problematic merely on principle. There's serious money at stake. COF's study finds that the "median reported salary for full-time CEO/CGOs was $160,000 in 2014, while for program officers it was $80,553."

So, yeah, climbing up that last rung makes a big difference financially. And that difference is even bigger at major foundations, where CEOs often pull down salaries in the mid-six figures.

What's going on here? Why does a foundation world that is primarily staffed by women not have more equity at the very top?

Well, let's start with the most obvious possibility: sexism. A Foundation Center study a few years ago found that "Foundation board members in 2009 were most likely to be white, male, and over age 50, regardless of foundation type or size." Family foundations do a little better in this regard, but as Rick Cohen wrote a few years ago in NPQ: "It's a man's world on foundation boards."

And here's big surprise: White guys over 50 are more likely to put their trust in... white guys over 50.

It's worth mentioning that most philanthropic fortunes are created by men, and often men who've risen to the tops of industries without many women CEOs. Just look at our lists of top donors from tech and finance, where a lot of the new philanthropy is coming from these days. There's not a single woman billionaire on the finance list and only one or two on the tech list.

At some level, it's not so surprising that if men make most of America's fortunes, women are underrepresented at the top of the sector that's giving away that money.

Of course, legacy foundations are a different deal, as the patriarch is long gone. Still, many have male-dominated boards, as I said, and those boards may be more inclined to hire men. We still live in a time, remember, that worships the kind of systemic, mechanistic, and hierarchical thinking most associated with men and diminishes the kind of collaborative and empathetic thinking often associated with women. Never mind that male leaders have presided over any number of gigantic screw-ups (like the 2008 financial crisis) and that a growing body of research suggests that women leaders are actually more effective.

Moving beyond the sexism explanation, the next possible reason for why more women aren't at the tops of foundations is that they're less inclined to take the personal hit those jobs entail. That explanation is heard often whenever the subject of women and leadership comes up, and there's a complicated and emotional debate on this. Just look at the explosion that surrounded Anne Marie Slaughter's Atlantic article, "Why Women Still Can't Have It All"—and then Sheryl Sandberg's de facto rebuttal, Lean In.

I don't want to wade into that swamp, so let's just end on a simple note: A good place to start addressing gender equity in top foundation jobs is in boardrooms.